"""
绘制同心圆

"""

import turtle

t = turtle.Pen()
my_colors = ("red", "green", "yellow", "black")
t.width(4)
t.speed(1)
for i in range(10):  # 0 1 2 3 4
    t.penup()
    t.goto(0, -i*10)  # 0, -100,-200,-300,-400
    t.pendown()
    t.color(my_colors[i%len(my_colors)])
    t.circle(15+i*10)  # 100,200,300, 400,, 500
turtle.done()  # 程序执行完，窗口仍然在
